This invention relates to a device for pointwise action on an information carrier, for instance for punching holes or printing characters composed by dots, dashes or the like, including means, such as a pointed head, a needle or the like, acting on the carrier and intended to strike on or press against a surface of the carrier.
In known character printing devices of the type referred to the printing members, which may comprise long threads, are generally operated by elongated electromagnets. The threads run in elongated guide means. These devices have several disadvantages. Because of the relatively large mass of the moving parts and also due to friction in the guide means the printing velocity is not very high. Moreover, by the elongated operating means the devices will have a considerable depth perpendicularly to a writing surface. Further, known devices for punching holes are space consuming and are characterized by a large moving mass and of considerable friction in bearings and the like.
The object of the present invention is to provide a device which operates at a higher speed and occupies considerably less space than the known devices. A device according to the invention is mainly characterized by a long arm which is disposed generally parallel to the surface and one end of which has the shape of or has a member acting on the carrier, its other end being associated with a spring element, the arm under the action of operating means being resiliently pivotable towards or away from the surface.
In a preferred embodiment of the invention the arm is associated with an armature energized by an electromagnet, which is arranged to receive electric pulses controlling the punching or the printing operation.
By the invention it is possible to use electromagnets of a construction which permits a very light armature. Also the arm can be of a very light material. Since the arm is supported by a spring element the friction during the turning movement of the arm can be entirely disregarded. Furthermore, a device according to the invention has no bearing which could be exposed to wear. It is also possible according to the invention to locate the greatest part of the moving mass close to the centre of pivoting so that the action of the mass as a bar to acceleration is reduced to a minimum.
Additional characterizing features and advantages of the invention will be seen in the following description in which reference is made to the attached drawings.